Cooling towers are widely used to dissipate process waste heat into the atmosphere. The interaction of water and air in cooling tower may be counter or cross current. In counter – flow cooling towers, heat and mass transfer takes place between a falling liquid film and the air stream moving counter currently. Film type fills are used in counter – flow cooling towers. Drift eliminators are provided at the top of the tower to avoid drift losses. Supply of fresh water is required to compensate blow-down losses, evaporation losses and drift losses. The transfer of heat from water to air takes place by convection and through evaporation of water.
